################################################################################
# The MIT License (MIT)
#
# Copyright (c) 2014 Kevin Haroldsen
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
################################################################################

import pyudev


def scan_devices():
    context = pyudev.Context()
    d = {}

    for device in context.list_devices(subsystem='block', DEVTYPE='partition'):
        devname = device.get('DEVNAME')
        gpt = device.get('ID_PART_ENTRY_SCHEME') == 'gpt'
        diskid = device.get('ID_PART_TABLE_UUID')

        if gpt:
            partid = device.get('ID_PART_ENTRY_UUID')
        else:
            diskid = int(diskid, 16)
            partid = int(device.get('ID_PART_ENTRY_OFFSET')) * 512

        d[(gpt, diskid, partid)] = (devname,)

    return d
